Light projecting technologies are essential for enabling several important device functionalities. For example, structured light projecting is deployed in 3D camera modules of mobile phones for recognizing facial features. The projected light reflects off the facial features can be captured by a detector and analyzed by algorithms to “perceive” the topology of the face. Accordingly, authentication, emoji generation, image capture orientation, and other various functionalities can be designed based on inputs of the facial feature recognition.
Current light projecting technologies are disadvantaged for high cost, large size, and low integration. In particular, conventional light projecting technologies do not fully utilize already available light sources to achieve the multiple functions sought, and instead utilize multiple projection means to achieve their objectives. These inefficiencies impose bottlenecks for the advancement of device structure and function built on or around the light projection features. Therefore, improvements over the existing light projecting technologies are desirable for both the consumer market and the industry.
Light projection is a key step for various applications such as 3D feature detection and 3D mapping. In conventional systems, multiple light sources and light projection subsystems are deployed in combination with one another to provide 3D feature detection and 3D mapping technology. For instance, many conventional systems mount both a distinct flood light illumination component and a distinct dot projector component to achieve the desired readings. In general, the light produced by the flood light component is broad beam light that spreads substantially as it propagates. Flood light is used to illuminate a surface of interest for image capture. The light produced by dot projector, on the other hand, is narrow beam light configured with substantially parallel rays that do not disperse or diverge with propagation as readily as flood light. Using two distinct light sources to achieve both flood light illumination and dot projection is inefficient and results in cumbersome modules that are ill suited for small environments.